One example of a castor of the kind referred to is disclosed in German Patent Specification No. 27 37 650. In this specification, there is described a castor having a body which comprises two parts, namely an upper part having the attachment means and the brake element and a lower part in which there is mounted an axle carrying two wheels which constitute the rolling means. The upper and lower body parts are united by an integral hinge portion situated adjacent to the peripheries of the wheels and remote from the attachment means. The hinge portion is elastically resilient. By flexing of the hinge portion, the lower body part and wheels can move downwardly relative to the upper body part to bring the wheels into engagement with the brake element and can move upwardly relative to the upper body part to disengage the wheels from the brake element.
It is disclosed in the aforesaid German specification that the hinge portion is sufficiently strong to support the load of the upper body part and of the weight of the piece of furniture to which the castor is fitted, without permitting the wheels to become disengaged from the brake elements.